The present invention relates to a method and apparatus for making a composite.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
Production of composites typically involves the coating of a produced product with a further layer, such as a plastic layer. The so-called SKINFORM® technology, described in the publication “Hochwertige Premiumoberflächen aus Spritzgieβ- und Reaktionstechnik” [High-Quality Premium Surfaces By Injection Molding and Reaction Technologies], published in the trade publication “Kunststoffe” [Plastics], issue October 2004, involves a process by which an injection-molded part of thermoplastic material is produced in a first step (cycle 1) through an injection molding or injection compression molding process. This part is then flooded in a further process step (cycle 2) with polyurethane material of a viscosity which is smaller than the viscosity of the thermoplastic material. This flooding step takes place in an enlarged cavity in which the component produced in cycle 1 has been introduced. The flooding material is hereby injected into the space between the component in the cavity and the cavity wall.
In a multi-component injection molding process, various injection molding materials are injected into different cavities in various steps. Composites can hereby also be produced depending on the configuration and disposition of the cavities.
Another thermoplastic processing process involves compression techniques in which material melts are introduced in an initially enlarged cavity which is then reduced in size in a compression step to its final size. As the cavity is compressed, material introduced into the initially enlarged cavity is pressed apart and dispersed throughout the entire cavity.
U.S. Pat. No. 4,207,049 describes a device for coating a plastic part, whereby an injection-molded part is initially produced in a cavity. The thus-filled cavity is enlarged after the injection-molded part has cured. As the cavity is substantially sealed off in relation to the ambient environment, a vacuum is created when the mold halves are separated to create a space for flooding material. Material is filled into the created space to form the outer surface, with the vacuum assisting the flooding step. The magnitude of the pressure below atmospheric depends on the degree of separation of the mold halves and on the tightness of the flooding space in relation to the ambient environment. The pressure below atmospheric also changes during introduction of the flooding material.
It would be desirable and advantageous to address prior art shortcomings.